1 // Iostreams base classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2015 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 //
26 // ISO C++ 14882: 27.4  Iostreams base classes
27 //
28 
29 #include <ios>
30 #include <limits>
31 
32 namespace std _GLIBCXX_VISIBILITY(default)
33 {
34 _GLIBCXX_BEGIN_NAMESPACE_VERSION
35 
36   // Definitions for static const members of ios_base.
37   const ios_base::fmtflags ios_base::boolalpha;
38   const ios_base::fmtflags ios_base::dec;
39   const ios_base::fmtflags ios_base::fixed;
40   const ios_base::fmtflags ios_base::hex;
41   const ios_base::fmtflags ios_base::internal;
42   const ios_base::fmtflags ios_base::left;
43   const ios_base::fmtflags ios_base::oct;
44   const ios_base::fmtflags ios_base::right;
45   const ios_base::fmtflags ios_base::scientific;
46   const ios_base::fmtflags ios_base::showbase;
47   const ios_base::fmtflags ios_base::showpoint;
48   const ios_base::fmtflags ios_base::showpos;
49   const ios_base::fmtflags ios_base::skipws;
50   const ios_base::fmtflags ios_base::unitbuf;
51   const ios_base::fmtflags ios_base::uppercase;
52   const ios_base::fmtflags ios_base::adjustfield;
53   const ios_base::fmtflags ios_base::basefield;
54   const ios_base::fmtflags ios_base::floatfield;
55 
56   const ios_base::iostate ios_base::badbit;
57   const ios_base::iostate ios_base::eofbit;
58   const ios_base::iostate ios_base::failbit;
59   const ios_base::iostate ios_base::goodbit;
60 
61   const ios_base::openmode ios_base::app;
62   const ios_base::openmode ios_base::ate;
63   const ios_base::openmode ios_base::binary;
64   const ios_base::openmode ios_base::in;
65   const ios_base::openmode ios_base::out;
66   const ios_base::openmode ios_base::trunc;
67 
68   const ios_base::seekdir ios_base::beg;
69   const ios_base::seekdir ios_base::cur;
70   const ios_base::seekdir ios_base::end;
71 
72   _Atomic_word ios_base::Init::_S_refcount;
73 
74   bool ios_base::Init::_S_synced_with_stdio = true;
75 
ios_base()76   ios_base::ios_base() throw()
77   : _M_precision(), _M_width(), _M_flags(), _M_exception(),
78   _M_streambuf_state(), _M_callbacks(0), _M_word_zero(),
79   _M_word_size(_S_local_word_size), _M_word(_M_local_word), _M_ios_locale()
80   {
81     // Do nothing: basic_ios::init() does it.
82     // NB: _M_callbacks and _M_word must be zero for non-initialized
83     // ios_base to go through ~ios_base gracefully.
84   }
85 
86   // 27.4.2.7  ios_base constructors/destructors
~ios_base()87   ios_base::~ios_base()
88   {
89     _M_call_callbacks(erase_event);
90     _M_dispose_callbacks();
91     if (_M_word != _M_local_word)
92       {
93 	delete [] _M_word;
94 	_M_word = 0;
95       }
96   }
97 
98   // 27.4.2.5  ios_base storage functions
99   int
xalloc()100   ios_base::xalloc() throw()
101   {
102     // Implementation note: Initialize top to zero to ensure that
103     // initialization occurs before main() is started.
104     static _Atomic_word _S_top = 0;
105     return __gnu_cxx::__exchange_and_add_dispatch(&_S_top, 1) + 4;
106   }
107 
108   void
register_callback(event_callback __fn,int __index)109   ios_base::register_callback(event_callback __fn, int __index)
110   { _M_callbacks = new _Callback_list(__fn, __index, _M_callbacks); }
111 
112   // 27.4.2.5  iword/pword storage
113   ios_base::_Words&
_M_grow_words(int __ix,bool __iword)114   ios_base::_M_grow_words(int __ix, bool __iword)
115   {
116     // Precondition: _M_word_size <= __ix
117     int __newsize = _S_local_word_size;
118     _Words* __words = _M_local_word;
119     if (__ix > _S_local_word_size - 1)
120       {
121 	if (__ix < numeric_limits<int>::max())
122 	  {
123 	    __newsize = __ix + 1;
124 	    __try
125 	      { __words = new _Words[__newsize]; }
126 	    __catch(const std::bad_alloc&)
127 	      {
128 		_M_streambuf_state |= badbit;
129 		if (_M_streambuf_state & _M_exception)
130 		  __throw_ios_failure(__N("ios_base::_M_grow_words "
131 					  "allocation failed"));
132 		if (__iword)
133 		  _M_word_zero._M_iword = 0;
134 		else
135 		  _M_word_zero._M_pword = 0;
136 		return _M_word_zero;
137 	      }
138 	    for (int __i = 0; __i < _M_word_size; __i++)
139 	      __words[__i] = _M_word[__i];
140 	    if (_M_word && _M_word != _M_local_word)
141 	      {
142 		delete [] _M_word;
143 		_M_word = 0;
144 	      }
145 	  }
146 	else
147 	  {
148 	    _M_streambuf_state |= badbit;
149 	    if (_M_streambuf_state & _M_exception)
150 	      __throw_ios_failure(__N("ios_base::_M_grow_words is not valid"));
151 	    if (__iword)
152 	      _M_word_zero._M_iword = 0;
153 	    else
154 	      _M_word_zero._M_pword = 0;
155 	    return _M_word_zero;
156 	  }
157       }
158     _M_word = __words;
159     _M_word_size = __newsize;
160     return _M_word[__ix];
161   }
162 
163   void
_M_call_callbacks(event __e)164   ios_base::_M_call_callbacks(event __e) throw()
165   {
166     _Callback_list* __p = _M_callbacks;
167     while (__p)
168       {
169 	__try
170 	  { (*__p->_M_fn) (__e, *this, __p->_M_index); }
171 	__catch(...)
172 	  { }
173 	__p = __p->_M_next;
174       }
175   }
176 
177   void
_M_dispose_callbacks(void)178   ios_base::_M_dispose_callbacks(void) throw()
179   {
180     _Callback_list* __p = _M_callbacks;
181     while (__p && __p->_M_remove_reference() == 0)
182       {
183 	_Callback_list* __next = __p->_M_next;
184 	delete __p;
185 	__p = __next;
186       }
187     _M_callbacks = 0;
188   }
189 
190   void
_M_move(ios_base & __rhs)191   ios_base::_M_move(ios_base& __rhs) noexcept
192   {
193     _M_precision = __rhs._M_precision;
194     _M_width = __rhs._M_width;
195     _M_flags = __rhs._M_flags;
196     _M_exception = __rhs._M_exception;
197     _M_streambuf_state = __rhs._M_streambuf_state;
198     _M_callbacks = std::__exchange(__rhs._M_callbacks, nullptr);
199     if (_M_word != _M_local_word)
200        delete[] _M_word;
201     if (__rhs._M_word == __rhs._M_local_word)
202      {
203        _M_word = _M_local_word;
204        _M_word_size = _S_local_word_size;
205        for (int __i = 0; __i < _S_local_word_size; __i++)
206 	 _M_word[__i] = std::__exchange(__rhs._M_word[__i], {});
207      }
208     else
209      {
210        _M_word = std::__exchange(__rhs._M_word, __rhs._M_local_word);
211        _M_word_size
212 	 = std::__exchange(__rhs._M_word_size, _S_local_word_size);
213      }
214     _M_ios_locale = __rhs._M_ios_locale;
215   }
216 
217   void
_M_swap(ios_base & __rhs)218   ios_base::_M_swap(ios_base& __rhs) noexcept
219   {
220     std::swap(_M_precision, __rhs._M_precision);
221     std::swap(_M_width, __rhs._M_width);
222     std::swap(_M_flags, __rhs._M_flags);
223     std::swap(_M_exception, __rhs._M_exception);
224     std::swap(_M_streambuf_state, __rhs._M_streambuf_state);
225     std::swap(_M_callbacks, __rhs._M_callbacks);
226     const bool __lhs_local = _M_word == _M_local_word;
227     const bool __rhs_local = __rhs._M_word == __rhs._M_local_word;
228     if (__lhs_local && __rhs_local)
229      std::swap(_M_local_word, __rhs._M_local_word); // array swap
230     else
231      {
232        if (!__lhs_local && !__rhs_local)
233 	 std::swap(_M_word, __rhs._M_word);
234        else
235 	 {
236 	   ios_base* __local;
237 	   ios_base* __allocated;
238 	   if (__lhs_local)
239 	     {
240 	       __local = this;
241 	       __allocated = &__rhs;
242 	     }
243 	   else
244 	     {
245 	       __local = &__rhs;
246 	       __allocated= this;
247 	     }
248 	   for (int __i = 0; __i < _S_local_word_size; __i++)
249 	     __allocated->_M_local_word[__i] = __local->_M_local_word[__i];
250 	   __local->_M_word = __allocated->_M_word;
251 	   __allocated->_M_word = __allocated->_M_local_word;
252 	 }
253        std::swap(_M_word_size, __rhs._M_word_size);
254      }
255     std::swap(_M_ios_locale, __rhs._M_ios_locale);
256   }
257 
258 _GLIBCXX_END_NAMESPACE_VERSION
259 } // namespace
260